Box office: Summer slump is expected to continue into Labor Day weekend

The box office's summer slump is likely to continue into Labor Day weekend, as the two newcomers -- "The November Man" and "As Above, So Below" -- are not expected to deliver huge numbers.

Heading into the four-day holiday weekend, pre-release audience surveys indicate that both could fail to outshine Marvel's August blockbuster "Guardians of the Galaxy" as it enters in fifth week in release. The movie based on the comic book cult favorite -- also the top film last weekend -- could add an additional $14 million to its total through Monday.

"Guardians," now the summer's highest-grossing movie domestically, has taken in $255.2 million to date in the U.S. and Canada. Worldwide, it has crossed the $500-million mark.

Both "The November Man" and "As Above, So Below" are expected to gross $9 million to $11 million over the four-day weekend, making it a tight race for No. 2.

"The November Man," which cost about $15 million to make, opened in about 2,750 theaters Wednesday. Relativity Media acquired the film for $3 million this year.

Based on the novel "There Are No Spies" by Bill Granger, the film follows former CIA agent Peter Devereaux (Pierce Brosnan) after he leaves quiet retirement for an assignment involving a power-hungry Russian leader.

The thriller, directed by John Erick Dowdle, follows a team of explorers as they venture into the catacombs beneath the streets of Paris.

The film, which cost about $5 million to make, used digital marketing campaigns to lure moviegoers. In a partnership with YouTube talent PewDiePie, the film created a series of videos that generated more than 15 million views.

It has already grossed $900,000 in Belgium, France and Switzerland.

Historically, Labor Day weekend tends to be slower for the box office. In 2007, "Halloween" had the holiday's biggest opening gross of roughly $30 million, according to Box Office Mojo.

Last Labor Day weekend, boy band One Direction's 3-D concert documentary "One Direction: This is Us" and action film "Getaway" lost to civil rights drama "The Butler." The four-day tally for "The Butler" was $20 million.

This weekend's new arrivals are unlikely to help pad this season's box office totals, which are down 15% from last year's record-breaking summer.